High-pressure gun for grease and oil



March 15, 1960 J. WAGNER 2,928,574

HIGH-PRESSURE GUN FOR GREASE AND on.

Filed sept. 24, 1957 The invention relates vto a high-pressure, gunforgrease and oil wherein the grease or oil is sucked by means of apiston pump driven by an electric motor out of a conrainer removablyattached to the rgun housing and is expelled at high pressure, from`-the nozzle which is closed .bymeans of a spring-loaded non-returnvalve, by .means of the lpump .piston which, `in its forward movement,closes the intake.

It is the object of the invention to develop a high-pressure gun of theaforesaid type in the sense of more com-- plete adaptation to roughservice anda high working States Patent pressure and to limit the heightofthe latter by means of a suitable device which is adjustable asrequired.

Thesolution of this problem according tothe invention consists in thatthe shaft of the motor, 'which isv flangeconnected in known Vmanner tothe gun housing, is coupled 'through a reduction gear to an eccentricwhich is mounted for 'rotation on a shaft located in the gun housing,and which rests'on the outer periphery of a ball-bearing'roller, thejournal of which is secured to a preferably bent rocking lever, the freeend of which rests. against the end `face of the pump piston rod which`projects into the gun housing, or'against the intermediate piston, sothat, yin this manner, the pump piston, which is constantly restored toits initial position by spring pressure, is reciprocated `in time'withvthe speed of rotation of the eccentric.

:In the -end of the pump cylinder which -projects out of the gunhousing, there is screwed a pressure-relief valve of which the valvetappet, which is provided with -arustoconical head and with an axialbore, is urged by plate springs against the valve seating. The force Aofthese plate springs is adjustable by means of a retaining -nu-t whichencases the springs and which comprises, at the end remote from the gunhousing, bores for discharging the excess lubricant delivered.

Further details of the invention vcan be .seen from the followingdescription of an example of 'an embodiment explained with reference 4tothe drawing. The drawing represents a longitudinal -section through theaxis lof the pump piston, partly broken away, of the high-pressure gunconstructed in accordance with the invention.

The housing of the grease and oil gun, which is constructed like apistol, is -made -of die-cast light metal or synthetic material and isgiventhe reference numeral 1. The housing comprises a handle 2 on theinside of .which is conveniently mounted a'rpress-button 3 by means ofwhich the driving motor 4, whichis llange-mounted on the housing 1 andis only -partly shown in the drawing, can be switched on and olf. Thegrease or oil container 5 is screwed into or otherwise secured in aneasily detachable manner, to the housing 1 below the nozzle orpressure-relief valve 6 of the gun.

The stub axle 7 of the motor 4, which projects into the housing l. endsin a pinion 8 which, together with the gearwheel 9 forms a reductiongear. The gearwheel 9 is rigidly coupled to the eccentric 10. The latteris mounted for rotation on the shaft 11 which is fixed on both sides inthe housing 1. The eccentric rests on the icc ` .piston A.16. The pump`piston v18 is guided in'thepu'mp cylinder k20 which is located Vinthe.gun housing by` meansof the is'etscrew 21. The spiral spring 19'rests:against .the pump cylinder' Zlland'urges the vspring:retainer 17against the Vintermediate Apiston 16; The force fo'fthe' spr-ingl9-ensures that the roller 12, which is mountedfor rotationfont-he'rocking lever .14, always :bears against theeccentric When theshaft 7 of the `driving'motor 4 rotates, Ztlre 'eccentric 10 `rocks thelever 14 in clockwise drectionin time with the yspeed of rotation ofthemotor. This leads to a displacement of Vthe pump piston 18 inside thepump vcylinder 20against the force of the spring 19'. The lastmentionedspring restores the .pump piston 181to its .initial :position Yeachtime.

:In the end vof 'the pump cylinder 20 remote .from v'the rocking lever14 there is vinstalled a :non-return valve 221, the stem 22 of which isguided in the vmem-berZ: lscrewed into the'pump cylinder 20. This memberisppr'ovided Awith vaxial passages for the @grease or oil. Thenon-return valve 22 vis urged against its valve `seating 'by means fofthe vspring .24. The spring tension can be `ladjustedfby means of theAmember 23 which canbe screwed backwards and forwards in Vthe'axialdirection- Y In the pump cylinder 20 and in the housing Y1=is a 'suctionbore 25 which, through a lter 26, 'provides .a

connection' between the bore in thejpump cylinder ,V20

and the grease or oil container 5. The suction bore 25 leads to a pointin the bore of the pump cylinder 2i) -which, when the pump piston 18 isdisplaced intothe position nearest .the driving motor 4-the suction.positionis not yet covered bythe pump piston but which is coveredthereby during the'delivery .stroke of the pumpjpiston .18.

yThe pump l18, 20 automatically sucks up the .grease or oil from thecontainer 5.

Screwed into the end of thepump cylinder .20 which i projects out of thegun housing 1 is a pressure-reliefvalve 6.1, With this Ithe maximumpermissible working ,pressure can be adjusted within wide limits-aboutv1.00 to 1000 atmospheres. This adjustment is elec-ted bymeans 'of theretaining nut 6 which shuts 0E .the-interior vof the pressure-reliefvalve k6 lfrom the outside. Mounted in the recess vin the nut 6 aretherplatevsprings 33 which are axially .displaceable on the valve tappet`31 provided :with an axial duct or 4bore 32 and which urge the"frustoconical head 31, of the valve tappet against Kthe vlve seating34. This pressure is variable Lby 'screwing the retaining nut 6 to agreater or lesser extent on the valveseating member.

[If Vthedelivery pressure vproduced by the pump piston 18 exceeds themaximum :pressure set yby means of Vthe :pressure-relief valve 6, thenthe head 31 o'f -the valve tappet is lifted from its valve seating 34against the con- -tact pressure exerted by the plate springs 33. Thegrease or oil delivered is then partially forced pas-t the plate springs33 and escapes through a by-pass conduit formed by the axial bores 35provided on the end face of the retaining nut 6', to the outside. Inthis manner, the pressure of the lubricant reaching the lubricant pointthrough the bore 3'2 in the valve tappet 31 and the highpressure tube 37secured by means of the sleeve 37 t0 the tappet 31, is lowered.

In the'drawing, the lubricantcontainer 5 is constructed,

in the form of a grease container. Mounted for Vsliding in the latter isa piston 27 which can be moved up and ,down by turning the threaded rod28 providedfwith a handle 30. ',A spiral spring 29 restng'onthe bottomof the container urges ythepiston 27 against the column of `grease lyingabove the latter. The lling of the grease container Sis preferablyeected asfollows:

.'lheempty container 5 is pushed, withthe piston Z7 advanced, into thebucket containing .the supply` of grease, and -the handle 30 isturnedback to the left. mannere acoherent column of grease, without any air,is

sucked into the V,container 5. The container 5 should..

then be screwed into the gun housing 1 in such amanner that V no airspace is formed betweenthe suction head of the gun and the container.The handle `30. of the threaded rod 28,V which was previously turned tothe left until it abutted against a stop is now turned to the rightuntil it abuts against'alstop and thus the piston 27.is pressedy againstthe column of grease under the pressure of the spiral spring 29.reliably pushed towards the suction head of the gun, and during thesuction stroke of the pump piston 18 it is lInthisV In -this manner, the.grease is the valve seating by plate springs the spring tension ofwhich is adjustable by means of a retaining nut which encases thesprings and which comprises, on the endface remote from the gun housing,axial bores for discharging the excess lubricant delivered. Y

7. A high-pressure gun having a gun housing, for use in dischargingmaterial such as grease and oil from a container'at high pressurethroughgand outofanozzle,

said gun having a housing, said container being removably connected tosaid housing,` the combination of an electric revolving motor built intosaid housing, a reciproeating piston pump connected to said housing andadapted to be disposed externally of said container and having an inletopening `communicating with said container, the

piston of said pump being oscillatable and spring biased towards aretracted suction position, transmission means between said electricmotor and said piston operable for propelling said pistonperiodicallyforwardly into a prest sure position comprising a revolubleeccentric cam driven from said motor, a bell crank lever having one armjournalled in said housing, a cam follower connected to said lever anddriven by said eccentric camV and including an anti-frictionbearingvdisposed substantially at right sucked through the bore into thepump cylinder 20 and from thence, during the delivery stroke of thepiston 1 8, it is forced through the adjustable pressure-relief valve 6to the lubricating point. t

The high-pressure gun for grease described above may also be used foroil. The'grease container is unscrewed and replaced by an oil containerequipped withv an oil-suction-pipe. i

-Iclaimz .j

1. A highpressure gun for grease and oil comprising in combination a gunhousing, a container for grease or oil detachably secured to saidhousing, an electric motor ange-connected to said housing, an ejectionnozzle, a spring-loaded non-return valve for `closing said nozzle,

a piston pump for sucking oil or grease out of the container and forejecting it under high pressure through said nozzle, awreduction gearinsaid housing, an'eccentnic coupled through said reduction gear withthe motor shaft, a ball-bearing rollerA against the outer periphery ofwhich the eccentric bears, and a rocking lever secured to the journal ofthe said roller, the free end of said lever actuating Ithe pump pistonreciprocating it in time with the speed of rotation of 'the eccentric. Y

2. A high-pressure gun as claimed in claim l, wherein the rocking leveris a bent lever.

, 3. A high-pressure gun as claimed in claim 1, wherein the free endofthe rocking lever bears againstfthe end face of' the pump piston rodprojecting into the gun housing.,

4. A highfpressure gun as claimed in claim l, wherein t the free end ofthe rocking lever bears against the end face of an intermediate piston,lon the pump piston rod projecting into the gun housing.

5. A high-pressure gun as claimedin claim 1, wherein the pump pistonwhen reciprocating is restoredateach stroke to its initial positionbyspringpressure. p 6. A high-pressure` gun as claimed in'claiiii l,characterised in that screwed into the end of the pump cylinderprojecting out of the gun housing is a pressure-relief `valve of whichthe valve tappet, which is provided with a frusta-conical headV and anaxial bore. is urged against t angle to the axis of said eccentric cam,the other arm of said lever` being in driving connection with saidpiston, `said piston beingactuatable to close said opening duringItheforward stroke, andy a 'rigid conduit structure connected'to saidhousing and supporting said nozzle dein-` ing a conduit extendingbetween said nozzle and said pump and including a pressure relief valvefor said nozzle,

whereby said eccentric cam will impart periodic impulses Y `to said camfollower land said lever will transmit these impulses to said pistonimpelling the piston periodically forwardly and the piston will beretracted by. said ,spring bias during the intervening time intervals,to .pump material out of said container into said conduit and throughsaid nozzle.

8. In a high-pressure gun, as claimed inclaim 7, said pressure reliefvalve comprising a valve seat formed in said conduit, a tapered valvehead movable to and from la valve closingV position onlsaid valve seatand having an internal bore, resilient means urging said valve headtowards said valveseat, whereby normally said valve head will engagesaid valve'seat andthe bore will conduct the lmaterial and,respectively, upon? the occurrence of excesspressure said valve headwill be lifted by the material oi the seat, said'conduit structureincluding means establishing a by-pass Vductfor the excess material whensaidvalve head is lifted off the seat, and means operable for adjustingthe force of said resilient means.

References Cited in the tile of this patent UNITEDzsTATEs PATENTS

